Gluconeogenesis Flashcards
Define Gluconeogenesis.
is the biosynthetic pathway that is responsible for the synthesis of glucose, which is a primary fuel source.
What is the normal blood glucose level?
80-120 mg/dl
What is the blood glucose level of a patient during an insulin reaction?
15-40 mg/dl
What can cause reduction in blood glucose levels for a patient experiencing an insulin reaction?
1) administration of insulin to levels that overcompensate for the bodies need.
2) intense exercise in the absence of proper food intake
Where does gluconeogenesis primarily occur?
In the liver.
What are the major precursors for glucose production?
1) Lactate
2) Glycerol
3) Amino Acids
What enzymes (and reactions) are involved in the irreversible steps in glycolysis?
1) hexokinase/glucokinase
Glucose –> Glucose 6-P
2) Phosphofructokinase-1 (PFK-1)
Fructose 6-P –> Fructose 1,6-diphosphate
3) Pyruvate kinase
Phoshoenolpyruvate (PEP) –> Pyruvate
What are the replacement enzymes (and reactions) in gluconeogenesis?
1a) Pyruvate carboxylase (biotin B7)
Pyruvate –> Oxaloacetate
1b) Phosphoenolpyruvate carboxykinase (PEPCK)
Oxaloacetate –> Phosphoenolpyruvate (PEP)
2) Fructose 1,6-diphosphatase
Fructose 1,6-P –> Fructose 6-P
3) Glucose 6-phosphatase
Glucose 6-P –> Glucose
Lactate is produced via ___________ glycolysis in what main three cell types?
Anaerobic
1) exercising muscle cells
2) red blood cells
3) fat cells
What is released from adipose stores of triglycerides?
Glycerol
What is generated by degradation of muscle proteins?
Amino Acids
What enzyme catalyzes the reaction of pyruvate and NADH from lactate? in what tissue?
Lactate dehydrogenase, in the LIVER.
What enzymes converts alanine to pyruvate?
Alanine aminotransferase
What enzyme catalyzes the reaction of the amino acid: Serine –> Pyruvate?
Serine dehydratase
How does glycerol come into the pathway for gluconeogenesis?
Glycerol –> [glycerol kinase] –> Glycerol 3-P –> [Glycerol 3-P dehydrogenase] –> Dihydroxyacetone phosphate (DHAP)
